Publications by authors named "Ricardo G Silva"

4 Publications

  • Page 1 of 1

Detection of the internal anatomy of lower anterior teeth using cone-beam computed tomography.

Aust Endod J 2021 Mar 2. Epub 2021 Mar 2.

Department of Restorative Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.

Morphology study of root canal systems is essential for a correct diagnosis, therapy and prognosis of root canal treatment. This study aimed to analyse the dental anatomy of the lower anterior teeth, using cone-beam computed tomography (CBCT). Lower anterior teeth were classified in terms of type, number and location of root canals, evaluating the bilaterality of anatomical occurrences and determining whether the gender and age influence the findings. We analysed 749 CBCT of patients attending the School of Dentistry for different reasons. Spearman's correlations and Wilcoxon signed-rank test were used to analyse data (α = 0.05). There was no significant correlation between gender (male and female) and anatomy of the canals 33 (P = 0.162), 32 (P = 0.815), 31 (P = 0.708), 41 (P = 0.422), 42 (P = 0.382) and 43 (P = 0.063). There was a significant correlation between age and anatomy of the canals 33 (P = 0.045), 32 (P = 0.033), 31 (P = 0.022), 41 (P = 0.000), 42 (P = 0.037) and 43 (P = 0.037). There was no significant correlation between gender and patients' age (P = 0.325). There was no anatomical difference between the bilateral pairs (right and left homologous teeth) (P > 0.05). The most common anatomical configuration was single-canal teeth (85.29%), followed by the configuration in which one canal leaves the chamber, divides into two and unite again (12.88%). Anatomy of the lateral incisors and lower canines does not change with the gender of patients. However, as age rises, single canals and the incidence of division into two canals ending in a single foramen also increases.
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March 2021

Prevention of intradialytic hypotension in patients with acute kidney injury submitted to sustained low-efficiency dialysis.

Ren Fail 2012 24;34(10):1238-43. Epub 2012 Sep 24.

Division of Nephrology, Hospital de Base, Sao Jose do Rio Preto Medical School, Sao Jose do Rio Preto, Brazil.

Objectives: This study evaluated the effects of a protocol aiming to reduce hypotension in acute kidney injury (AKI) patients submitted to sustained low-efficiency dialysis (SLED).

Methods: Patients were randomly assigned to two SLED prescriptions-control group, dialysate temperature was 37.0°C with a fixed sodium concentration [138 mEq/L] and ultrafiltration (UF) rate; and profiling group, dialysate temperature was 35.5°C with a variable sodium concentration [150-138 mEq/L] and UF rate.

Results: Sixty-two SLED sessions were evaluated (34 in profiling and 28 in control). Patients (n = 31) were similar in terms of gender, age, and Sequential Organ Failure Assessment (SOFA) score. Dialysis time, dialysis dose, and post-dialysis serum sodium were similar in both groups. The profiling group had significantly less hypotension episodes (23% vs. 57% in control, p = 0.009) and achieved higher UF volume (2.23 ± 1.25 L vs. 1.59 ± 1.03 L in control, p = 0.04) when compared with control group.

Conclusions: SLED protocol with modulation of dialysate temperature, sodium, and UF profiling showed similar efficacy but less intradialytic hypotension when compared with a standard SLED prescription.
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April 2013

Shear bond strength and ultrastructural interface analysis of different adhesive systems to bleached dentin.

Microsc Res Tech 2011 Mar;74(3):244-50

School of Dentistry, University of Ribeirão Preto, Ribeirão Preto, Brazil.

Background: It remains unclear as to whether or not dental bleaching affects the bond strength of dentin/resin restoration.

Purpose: To evaluated the bond strength of adhesive systems to dentin submitted to bleaching with 38% hydrogen peroxide (HP) activated by LED-laser and to assess the adhesive/dentin interfaces by means of SEM.

Study Design: Sixty fragments of dentin (25 mm²) were included and divided into two groups: bleached and unbleached. HP was applied for 20 s and photoactivated for 45 s. Groups were subdivided according to the adhesive systems (n = 10): (1) two-steps conventional system (Adper Single Bond), (2) two-steps self-etching system (Clearfil standard error (SE) Bond), and (3) one-step self-etching system (Prompt L-Pop). The specimens received the Z250 resin and, after 24 h, were submitted to the bond strength test. Additional 30 dentin fragments (n = 5) received the same surface treatments and were prepared for SEM. Data were analyzed by ANOVA and Tukey's test (α = 0.05).

Results: There was significant strength reduction in bleached group when compared to unbleached group (P < 0.05). Higher bond strength was observed for Prompt. Single Bond and Clearfil presented the smallest values when used in bleached dentin. SEM analysis of the unbleached specimens revealed long tags and uniform hybrid layer for all adhesives. In bleached dentin, Single Bond provided open tubules and with few tags, Clearfil determined the absence of tags and hybrid layer, and Prompt promoted a regular hybrid layer with some tags.

Conclusions: Prompt promoted higher shear bond strength, regardless of the bleaching treatment and allowed the formation of a regular and fine hybrid layer with less deep tags, when compared to Single Bond and Clearfil.
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March 2011

Tetanus-induced acute kidney injury in a renal transplant recipient.

Am J Trop Med Hyg 2007 Aug;77(2):400-2

Division of Nephrology, Hospital de Base, São Jose do Rio Preto Medical School, 15090-000 São José do Rio Preto, SP, Brazil.

A 48-year-old renal transplant recipient who developed tetanus 6 years after transplantation is described. His immunosuppressive protocol was mofetil mycophenolate, sirolimus, and prednisone. The patient presented symptoms of severe tetanus with autonomic dysfunction, requiring ICU care and mechanical ventilation. His clinical course was marked by development of tetanus-induced acute kidney injury and sepsis. He was discharged after 37 days of hospitalization with recovered renal function. Tetanus is a preventable disease associated with a high fatality rate. Its treatment is difficult and requires specialized and intensive care. This case highlights the crucial importance of following adequate immunization guidelines in transplant recipients.
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August 2007